Rotary locking mechanism, which is preferably intended for lock cylinders

ABSTRACT

The invention relates to a rotary locking mechanism which is preferably intended for lock cylinders. The inventive mechanism includes an electric motor, a locking bolt, an inertial rotating mechanism which converts the rotation of the motor into a rectilinear movement along the axis of the locking bolt, an elastic energy accumulator which is arranged in opposition to the backward retraction travel of the locking bolt and a rectilinear guide mechanism for the working extension/retraction travel of the locking bolt.

FIELD OF THE INVENTION

This invention concerns a rotary locking mechanism, preferably for lockcylinders, as used in electromechanical locks that are operated by anelectromechanical key incorporating a self-contained power source, andwhich comprise a cylinder that is housed in a traditional mechanicallock, and which comprises a stator inside which there is housed andoperated rotationally a rotor with a housing for one such key, whichwhen turned, causes the rotor to rotate and an eccentric thereof whichis able to cause the lock to open, whose rotor has a housing for alocking bolt that is retractable in one said stator in which the rotarylocking mechanism itself is housed which in the presence of such keycauses extension and retraction of the locking bolt. Said rotor haselements to transmit energy and information between the two electricalcircuits.

PRIOR STATE OF THE ART

A known lock in this field is described in patent FR 2 808 552, byMutter, in which is described a locking mechanism for electroniccylinders, comprising a locking bolt housed in the rotor and whichprevents it from moving. Said bolt is kept housed in the rotor by meansof a cam operated by a motor. On unlocking, the motor rotates said cam,releasing the bolt and allowing the bolt to withdraw from its housing,thus allowing the rotor to rotate and the lock to operate.

Another known lock is described in patent U.S. Pat. No. 5,628,217, byHerrera, in which is described an electromechanical cylinder whoselocking mechanism comprises a locking bolt housed in the rotor and whichprevents movement thereof. Said bolt is kept housed in the rotor bymeans of a motor that operates a cam that converts the rotary movementof the motor into linear movement. Said cam is linked to a locking bolt.At the time of unlocking, the motor rotates said cam, withdrawing thebolt from the housing, allowing the user to rotate the rotor by means ofthe key and thus open the lock.

Another known lock is described in patent U.S. Pat. No. 6,227,020 B1, byLerchner, which describes a locking device applicable to electroniccylinders. The mechanism comprises an actuator governed by a motor, anda locking element preventing the rotor from rotating. When the actuatoris in the unlocked position, movement of the locking element is allowedand when the rotor rotates, it moves the locking element towards acertain position. When the actuator is in the locking position, onattempting to rotate the rotor, it cannot move the locking elementbecause this is prevented by the actuator.

A drawback of this type of locking mechanism, described in the abovepatents, is that it is not possible to guarantee locking of the rotor ifthe key is already inserted and turned in relation to its initialposition. If the rotor housing is not aligned with the locking bolt, themechanism cannot move when the motor is operated to lock the lock.

Thus to guarantee locking, the motor should be operated when the key iswithdrawn from the rotor housing when it is in its initial position.Otherwise, the bolt is left outside the rotor housing, allowing therotor to rotate and the lock is left open.

Another drawback of this kind of mechanism is that they are not suitablefor use as a locking system in an electronic cylinder operated with anelectronic key, where the power supply of the cylinder comes from apower source integrated in the key itself. This is because they arebi-stable systems, that is to say, they have two stable positions, onelocked and the other unlocked. Transition from one position the other isnormally achieved by operating the motor. Therefore, it is necessary toapply energy to the motor in order to place it in its locking positionand thus lock the mechanism. Because, on withdrawing the key from thecylinder rotor, the power source that supplied the cylinder is alsowithdrawn, it is not possible to operate the motor in order to get thecylinder to lock.

The main disadvantage of the mechanisms described in the above patentsis the need to operate the motor to lock the mechanism and thus closethe lock. If the cylinder mechanism receives its power through theelectronic key itself, on withdrawing said key the power supply is cutoff. Consequently, to lock the mechanism, the motor needs to be operatedby means of a power supply included in the cylinder itself.

Another disadvantage of some of the described mechanisms is that themotor has to overcome some type of friction during its actuation. Thisfriction can cause wear to the parts that make up the mechanism ornon-actuation in the event of excessive friction.

Friction existing during actuation of the mechanism requires the use ofmotors of suitable mechanical characteristics to overcome such friction.This involves higher cost and restrictions on choosing the required typeof motor.

The aforementioned mechanisms require very high levels of accuracyduring manufacture to achieve friction-free parts of minimum dimensions.

DESCRIPTION OF THE INVENTION AND ADVANTAGES

The mechanism provided by this invention comprises: an electric motor, alocking bolt, a plurality of inertial rotating means for convertingmotor rotation to rectilinear movement along the axis of the lockingbolt, an elastic energy accumulator means in opposition in relation tothe retraction travel of the locking bolt, and a plurality ofrectilinear guidance means for the operative extension/retraction travelof the locking bolt; whereby said electric motor is electricallyactivated by the energy source of the key inserted in its rotor housing,said inertial conversion rotating means comprises an axially fixedrotary support which is linked to the electric motor shaft, one or aplurality of inertial rotating elements that, in respect of a coaxialrotation axis with the electric motor, produce an increase in theinertial momentum as rotation speed increases, an actuator linked to thelocking bolt and coaxially movable with same, a rotational/linearconversion means disposed between the inertial rotary elements and thelinked actuator of the bolt, said elastic energy accumulator means is acompressible helical spring that is fitted between the linked movableactuator of the locking bolt and the rotary support axially fixed to theelectric motor shaft, and such rectilinear guidance means comprises atleast two guide shafts or rods which, by being linked to one of saidmovable actuator elements and rotary support, penetrate through theother element at diametrically opposed positions.

That is to say, the proposed mechanism essentially comprises thefollowing elements:

-   -   An electric motor that rotates when electrical energy is        supplied thereto.    -   A conversion mechanism whose function is to convert rotary        movement of the electric motor into linear movement along a        linear direction, which can be used to achieve cylinder        unlocking. This mechanism offers minimal inertia against        rotation when rotational speed is minimal. As the rotational        speed increases, the parts that make up the conversion mechanism        are distributed in such a way that their inertial momentum is        increased in respect of the rotational axis, increasing inertia        against rotation around such rotational axis. The conversion        mechanism consists of the following parts:    -   A rotary support, whose function is to transmit motor rotation        to the entire conversion system.    -   One or several mobile inertial elements set out in such a way        that on increasing the rotational speed of the assembly, they        are distributed in such a way that their inertial momentum is        increased in respect of the rotational axis.    -   An actuator able to move linearly in one direction, whose        function is to move a locking element.    -   A transmission element whose function is to transmit rotational        movement of the inertial element into a linear movement of the        actuator element along a linear direction. This movement can be        used to unlock the cylinder.    -   A locking element that can be fully inserted in a housing        existing in the cylinder rotor. Said locking element, in its        locked position prevents the cylinder rotor from being rotated        with the key, and in its unlocked position allows the cylinder        rotor to be rotated with the key.    -   A return element able to store mechanical potential energy when        deformed, whose function is to return the actuator element of        the conversion system to its rest position.

Joining of these elements is achieved as follows:

-   -   The electric motor shaft and the conversion system are joined        via the rotary support. In this way, when the electric motor        rotates, the conversion mechanism rotates.    -   The rotary support and inertial elements are joined in such a        way that the support transmits its rotary movement to said        inertial elements, and allowing the movement of said inertial        elements in such a way that they increase their inertial        momentum in relation to the rotation axis as the rotation speed        increases.    -   The inertial elements and the actuator element are joined via        the transmission element in such a way that movement caused by        rotation of the inertial elements is converted into linear        movement of the actuator element.    -   The return element is set out in such a way that linear movement        of the actuator causes the return element to deform so that        mechanical potential energy is stored in the return element.    -   The actuator and locking element are joined together in such a        way that the linear movement of the actuator causes withdrawal        of the locking element from the rotor housing, allowing the        rotation same and the ensuing opening of the lock.

According to a variant of an embodiment of this invention, because theinertial rotating elements are weights of equal mass, saidrotational/linear conversion means consists of filaments equal in numberto that of the weights and which are held to the movable actuator toextend rectilinearly through an equal number of holes in the rotarysupport, and each one has one of these weights at its tip. Preferably,these weights and filaments are two in diametrically opposed positionsin relation of the rotation axis.

According to another variant of an embodiment of this invention, theinertial rotating elements are weights of equal mass, saidrotational/linear conversion means consists of rods joined to saidrotary support and movable actuator by an equal number of firstknuckles, while each of these rods has a central second knuckle to whichone of the weights is disposed. Preferably, said inertial rotatingelements are weights of equal mass, said rotational/linear conversionmeans consists of rods joined to said rotary support and movableactuator by means of an equal number of first knuckles, while each ofthese rods has a central second knuckle to which one of the weights isdisposed.

The main advantages of this invention are as follows:

-   -   This invention provides a locking mechanism for electronic        cylinders, in which locking of the mechanism is ensured in any        situation. The system should be fault-tolerant, that is to say,        the mechanism should ensure mechanical locking of the lock even        in the event of failure of the electronic part.    -   The provided system uses a motor to operate the mechanism. The        mechanical characteristics of the motor are not critical to good        operation of the mechanism in locking and unlocking operations,        with the ensuing cost savings when choosing the motor.    -   Furthermore, because a motor of certain mechanical        characteristics is not required, it is possible to choose a        motor of minimal dimensions, thus saving space, which is so        scarce in this type of locks.    -   The mechanism does not need any gearing system to multiply the        force of the motor, thereby simplifying the mechanism and saving        on cost.    -   The system should guarantee mechanical locking of the lock        without having to activate the motor. In other words, merely by        disconnecting the energy operating the motor, the mechanism        should return to the locked position of its own accord.    -   The provided system entails minimal friction of its parts during        operation. In this way, the wear of the device is minimal, with        the ensuing increase to the life of the cylinder.

DRAWINGS AND REFERENCES

For a better understanding of the nature of this invention, in theattached drawings a preferred form of an industrial embodiment is shown,which is an example that is merely illustrative and not restrictive.

FIG. 1 shows an example of a mechanism according to the invention inrest position, sectioned through the middle with the exception of theelectric motor and its shaft (1).

FIG. 2 shows an example of the same mechanism as FIG. 1, but inactivated position.

FIG. 3 shows a view from the top of the same mechanism as FIGS. 1 and 2,without the casing or enclosure (11).

FIG. 4 shows a second variant of a mechanism according to the inventionin rest position.

FIG. 5 shows the same variant as FIG. 4, but in activated position.

FIG. 6 shows a view from the top of the same variant of FIGS. 4 and 5.

These schematic figures use the following references:

-   1.—Electric motor and motor shaft-   2.—Inertial rotating elements or weights-   3.—Fixing filaments or rotational/linear transmission element-   4.—Rotary support-   5.—Movable actuator-   6.—Locking bolt-   7.—Knuckled rod or rotational/linear transmission element-   8.—Return spring-   9.—First knuckle-   9 a.—Second knuckle-   10.—Guide shafts or rods-   11.—Casing or enclosure housing the mechanism

DESCRIPTION OF A PREFERRED EMBODIMENT

Regarding the drawings and references listed above, the attacheddrawings illustrate two variants of embodiments of the invention forexplanatory and non-restrictive purposes.

FIG. 1 shows an example of a system of this type in rest position, whereits key elements can be identified:

-   -   The conversion mechanism consists of the rotary support (4)        joined to the motor shaft (1). Said support (4) has two        diametrically opposed holes, through which two independent        filaments (3) are fed. At one end of the filaments (3), two        equal mass parts are fixed, which from now on shall be called        weights (2) and which are the inertial elements. The other end        of both filaments (3) is fixed to the movable actuator (5), in        diametrically opposed positions. The movable actuator (5) can        move linearly in the direction of the rotation axis. Said        movable actuator (5) is guided in its movement by two guide        shafts or rods (10).    -   The transmission element is comprised of the filaments (3).    -   The locking element is a cylindrical bolt (6) that is joined to        the movable actuator (5).    -   The recovery element for elastic energy accumulation is a        helical compression spring (8) fitted between the rotary support        (4) and the movable actuator. When the movable actuator moves        towards the unlocked position, said spring is compressed and        stores mechanical potential energy.

The operation of the mechanism during unlocking is as follows:

-   -   On supplying electrical energy to the motor, its shaft starts        rotating, which rotates together with the rotary support (4).        The rotation of said support causes rotation of the weights (2)        located at the ends of the filaments (3). Due to the effect of        centrifugal force, said weights (2) tend to separate in        diametrically opposed directions, separating from the rotation        axis and increasing the inertial momentum of the entire inertial        element.    -   As the weights (2) of the inertial element separate, the        filaments (3) holding them and which are joined to the movable        actuator, tend to move said support along the length of the        motor shaft, approaching the rotary support (4).    -   The movement of the movable actuator (5) causes withdrawal of        the locking bolt (6) from the rotor housing, allowing the        cylinder rotor to rotate and open the lock.    -   The approach of the movable actuator (5) and the rotary support        (4) causes deformation of the recovery spring (8) and storage of        potential mechanical energy, while the mechanism remains in the        activated position due to the rotating effect of the electric        motor (1).    -   The movement of the movable actuator causes withdrawal of the        locking element from the rotor housing, allowing the cylinder        rotor to rotate, opening the lock.

FIG. 2 shows the arrangement of the key elements of the describedmechanism when it is in the activated position.

The operation of the mechanism during locking is as follows:

-   -   On removing electrical power to the motor (1), the motor (1)        does not contribute to rotation of the rotary support (4).    -   The friction of the parts that make up the entire system causes        a reduction in the angular speed of the entire assembly.    -   As the rotation speed to the weights (2) reduces, the        centrifugal force keeping the weights (2) separate from the        rotation axis is reduced. The reduction in the centrifugal force        allows the weights (2) to approach the rotation axis, reducing        their inertial momentum. In this way, the filaments (3) that        hold the weights and which are joined to the movable actuator no        longer contribute to approaching the movable actuator to the        rotary support (4).    -   The mechanical potential energy stored in the compressed return        spring tends to separate the movable actuator from the rotary        support (4).

The movement of the movable actuator towards its rest position causesinsertion of the locking element into the rotor housing, preventing thecylinder rotor from rotating and causing the lock to close.

FIG. 4 shows another example of a system of this type in rest position,where its key elements are identified:

-   -   The conversion mechanism consists of a rotary support (4) joined        to the motor shaft and a movable actuator (5). To said rotary        support (4) and in diametrically opposed positions, the ends of        two rods or rotational/linear transmission elements (7) are        fixed by means of two knuckles (9), in such a way that the rods        are allowed to rotate in relation to said support. At the other        end of both rods, two parts of equal mass (2) are fixed, which        from now on shall be called weights (2) and which constitute the        inertial elements. In the movable actuator (5) and in        diametrically opposed positions, the ends of the two rods or        rotational/linear transmission elements (7) are fixed by means        of two first knuckles (9) in such a way that the rods or        rotational/linear transmission elements (7) are allowed to        rotate in relation to said support. The other ends of both rods        or rotational/linear transmission elements (7) are articulated        by means of an equal number of second knuckles (9 a) to which        the aforementioned weights (2) are fixed.    -   The transmission element comprises the knuckled rods or        rotational/linear transmission elements (7).    -   The locking element is a locking bolt (6) that is joined to the        movable actuator (5).    -   The recovery element is a spring (8) fitted between the rotary        support (4) and the movable actuator (5). As the movable        actuator (5) moves towards the unlocked position, said spring        (8) is compressed and stores mechanical potential energy.

The operation of the mechanism during unlocking is as follows:

-   -   On supplying electrical energy to the motor, its shaft starts to        rotate, which rotates together with the rotary support (4). The        rotation of the support causes rotation of the weights (2)        located at the ends of the rods or rotational/linear        transmission elements (7). Due to the effect of centrifugal        force, said weights (2) tend to separate in diametrically        opposed directions, separating from the rotation axis and        increasing the inertial momentum of the entire inertial element.    -   As the weights (2) separate, the rods or rotational/linear        transmission elements (7) that hold them tend to move the        movable actuator (5) along the length of the direction of the        motor shaft (1), approaching the rotary support (4).    -   The movement of the movable actuator (5) causes withdrawal of        the locking bolt (6) from the rotor housing, allowing the        cylinder rotor to rotate and open the lock.    -   The movement of the movable actuator (5) causes the return        spring (8) to deform and store potential mechanical energy,        while the mechanism remains in the activated position due to the        rotating effect of the electric motor (1).    -   The movement of the movable actuator (5) causes withdrawal of        the locking bolt (6) from the rotor housing, allowing the        cylinder rotor to rotate and open of the lock.

FIG. 5 shows the arrangement of the key elements of the describedmechanism when it is in the activated position.

The operation of the mechanism during locking is as follows:

-   -   On removing electrical energy from the motor (1), the motor (1)        does not contribute to the rotation of the inertial rotary        support (4).    -   The friction of the parts that make up the entire system causes        a reduction in the angular speed of the entire assembly.    -   On reducing the rotational speed of the weights (2), the        centrifugal force keeping the weights (2) separate from the        rotation axis is reduced. The reduction of the centrifugal force        allows the two weights (2) to approach the rotation axis,        reducing their inertial momentum.    -   The mechanical potential energy stored in the compressed return        spring (8) tends to separate the movable actuator (5) from the        support (4).    -   The movement of the movable actuator (5) towards its rest        position causes insertion of the locking bolt (6) into the rotor        housing, preventing the cylinder rotor from rotating, thus        closing the lock.

In the described mechanisms, it might happen that, on deactivating thesystem, the rotor is rotated a certain angle in such a way that thelocking bolt (6) is not aligned with its housing in the rotor, in such away that the locking bolt (6) cannot house itself in the rotor. In thiscase, the locking bolt (6) prevents the movable actuator (5) from movingin the direction of the axis.

In this situation, because the rotation of the inertial element stops,the centrifugal force that maintains the weights (2) separate from therotation axis and the return spring (8) compressed disappears. However,said return spring (8) cannot decompress because the movable actuator(5) cannot move in the direction of the axis because the locking bolt(6) cannot house itself in the rotor.

When the rotor rotates in such a way that the locking bolt (6) isaligned with its rotor housing, the return spring (8) will push themovable actuator (5), which in turn will push the locking bolt (6),inserting said locking bolt (6) into its housing and preventing therotor from rotating. That is to say, no key needs to be present toensure that the lock is perfectly closed, rather the act of physicallyremoving the certain key compels the system to tend to its lockingstate, where the bolt (6) tries to house itself in its rotor housing andwill do so as soon as it can; if on removing the key, there is somenon-alignment between the bolt (6) and its housing, as soon as anyattempt is made to rotate the rotor without the key, the requiredalignment will be achieved and rotary locking of the rotor will beestablished.

1. Rotary locking mechanism, for lock cylinders in electromechanicallocks that are operated by means of an electromechanical keyincorporating a self-contained energy source, and which comprises acylinder that is housed in a traditional mechanical lock and whichcomprises a stator, in the core of which a rotor is housed and operatesrotationally, said rotor has a housing for one said key which, on beingturned, causes rotation of the rotor and an eccentric thereof which iscapable of causing opening of the lock, which rotor has a housing for alocking bolt which is retractable in one said stator in which is housedthe actual rotary locking mechanism which in presence of said keyproduces extension and retraction of the locking bolt (6), comprising:an electric motor (1), a locking bolt (6), an inertial rotating meansfor converting rotation of the motor (1) into a rectilinear movementalong the axis of said locking bolt (6), an elastic energy accumulatingmeans arranged in opposition to the retraction travel of the lockingbolt (6), and rectilinear guide means for providing rectilinear guidanceof the operating extension/retraction travel of the locking bolt (6);wherein said electric motor (1) is activated electrically by the energysource of the key inserted in its housing or in the rotor, said inertialconversion rotating means comprises an axially fixed rotary support (4)which is linked to the shaft of the electric motor (1), one or severalinertial rotating elements (2) which, in relation to a coaxial rotationaxis with that of the electric motor (1), produce an increase in theinertial momentum on increasing their rotational speed, an actuatorlinked to the locking bolt (6) and which is coaxially movable therewith,a rotational/linear conversion means (3, 7) that is installed betweenthe inertial rotating elements (2) and the actuator (5) linked to thelocking bolt (6), said elastic energy accumulator is a compressiblehelical spring (8) that is installed between the movable actuator (5)linked to the locking bolt (6) and the rotary support (4) axially fixedto the shaft of the electric motor (1), and such rectilinear guidancemeans comprises at least two guide shafts or rods (10) that, joined toone of said elements of movable actuator (5) and rotary support (4),closely penetrate through the other of these elements in diametricallyopposed positions.
 2. Rotary locking mechanism, for lock cylinders, inaccordance with claim 1, wherein said inertial rotating elements (2) areweights (2) of equal mass, said rotational/linear conversion meanscomprises several filaments (3) in equal number to that of the weights(2) which are held to the movable actuator (5) and extend rectilinearlythrough the same number of holes in the rotary support (4) and each onehas one of said weights (2) at its end.
 3. Rotary locking mechanism, forlock cylinders, in accordance with claim 2, wherein said weights (2) andfilaments (3) are both positioned in diametric opposition in relation tothe rotation axis.
 4. Rotary locking mechanism, for lock cylinders, inaccordance with claim 1, wherein said inertial rotating elements (2)comprise several weights (2) of equal mass, said rotational/linearconversion means comprises rotational/linear transmission rods orelements (7) that are joined to said rotary support (4) and movableactuator (5) by means of the same number of first knuckles (9) whileeach one of the rotational/linear transmission rods or elements (7) hasa central second knuckle (9 a) to which one of said weights (2) isdisposed.
 5. Rotary locking mechanism, for lock cylinders, in accordancewith claim 1, wherein said weights (2) and rotational/lineartransmission rods or elements (7) are two in diametrically opposedpositions.
 6. Rotary locking mechanism, for lock cylinders, inaccordance with claim 1, wherein the rotation of the motor (1) providesfor rotations of the rotary support (4) which is joined to the inertialrotaries or weights (2) by means of filaments (3) or articulated rods(7), whereby rotation provides for centrifugal separation of the weights(2) in relation to their rotation axis with the ensuing movement of theactuator support (5) against compression of the return spring (8).